In the quest for reduced friction and wear between rubbing surfaces, several different lubrication methods have been employed. Solid lubricants are often used either alone or in conjunction with liquid lubricants to provide an easily sheared interface between sliding members. One class of compounds that exhibit solid lubricating ability is the lamellar, or layer lattice solids. These compounds contain crystal structures in which the interatomic bonding is significantly weaker in one dimension. This results in a layer structure which is easily sheared in certain directions. The best examples of these types of compounds are graphite and molybdenum disulfide (MoS.sub.2). In some applications, however, the use of graphite or molybdenum disulfide is inappropriate. For instance, chemical incompatabilities between these lubricants, surfaces, and environments may limit their applications. Such as the case when graphite or molybdenum disulfide are used in oxygen containing environments at high temperatures. Also, in some applications carbon and sulfur contamination is undesirable. Further, the use of a heavy metal such as molybdenum may also be impermissible. Thus arises the necessity for a layer lattice solid lubricant which overcomes the above-mentioned drawbacks.
It is thus an object of the present invention to provide a solid lubricant to reduce frictional coefficients between contacting surfaces such as aluminum oxide surfaces.
It is a further object of the present invention to produce a solid lubricant for lubricating contacting surfaces at high temperatures.
The present invention relates to the use of aluminum hydroxides as solid lubricants for alumina, aluminum oxides, ceramics and other oxide materials. Aluminum oxide hydroxide (boehmite) and aluminum trihydroxides are preferred compositions for such lubricating purposes. In particular, the use of boehmite in an aqueous solution is disclosed as a means to reduce frictional coefficients between contacting surfaces.